150 



Polyplectana galatheae n. sp. 



Tahiti. The Galathea Expedition. One specimen. 



The single specimen at hand measures ca. 15 cm in length by 

 1,5 cm in diameter. The colour is uniformly grey. It has 25 

 tentacles, which are so contracted that neither the number of the 

 digits nor the presence or absence of a web can be ascertained. 

 On the oral disk there are eye-spots, The cartilaginous ring is well 

 developed and almost wholly encloses the weak, calcareous ring, 

 which is quite alike that in oculata. There are numerous polian 

 vesicles and a single stone-canal. The madreporite is, as in oculata, 

 elongated along the one side of the stone-canal. The gonads are 

 short and thick and not much branched. The alimentary canal is 

 not distinctly divided into oesophagus, stomach and intestine, but 

 it has a large loop. The ciliated funnels are of the usual size and 

 shape. They are found on the mesenteries close to the body-wall. 



The anchors from the anterior end of the specimen (Fig. 13. 8) 

 are not different from those more posteriorly (Fig. 13. 7). They 

 measure ca. 300 /it in length by 170 fi in width. The anchor- 

 plates from the anterior end of body (Fig. 14. 3) measure ca. 200 

 fi in length by 170 /i in width, and those from the posterior end 

 (Fig. 14. 6) measure ca. 230 [i in length by 170 fi in width. The 

 plates from the two ends of the specimen differ in the shape of 

 the articular hole, in the anterior plates being usually smooth, in 

 the posterior plates usually being supplied with some few teeth in 

 the anterior margin. 



Rods and miliary granules are wanting in the specimen at hand, 

 but in the longitudinal muscles there are oval plates, measuring 

 ca. 25 |i* in length. 



This specimen cannot be referred to any of the species hitherto 

 known. The shape of the calcareous ring puts it closest to oculata, 

 from which species it differs distinctly in the shape of the anchors 

 and anchor-plates. That it cannot be referred to the aame species 

 as Clark's specimen from Tahiti, (tahitiensis) characterized by 

 the unusually large miliary granules, is evident as miliary granules 

 are totally wanting in the specimen at hand. 



